A known image forming apparatus having a duplex printing function includes an ejection roller, a re-feeding roller, and a fixing roller, which are driven by a common motor. The ejection roller is a switchback roller which is rotatable in both forward direction and reverse direction. The ejection roller is disposed on an opposite side of the fixing unit from the re-feeding roller.
Due to this positional relationship, a transmission mechanism for transmitting a drive force to the fixing unit and a transmission mechanism for transmitting a drive force to the ejection roller are disposed in the vicinity of the motor.